No...

I think Charlie explained it well, but I thought that I would add that if someone said that to me, I would think, 'So you have sisters but you don't want to mention them, or you did something other than go on a trip as well?... hmm confusing' Also, I wouldn't recommend using 'sth'. It's not immediately obvious what you mean and also a bit weird to use when you are asking for help, as it is a very slangy.